Synthesis of Yellow Fluorescence Carbon Dots for the Applications of Vitamin B12 Detection and Cell Imaging

In this work, bright yellow fluorescent and multifunctional carbon dots (N-CDs) were prepared by hydrothermal method from O-phenylenediamine and 4-aminobenzoic acid. The fluorescence characterization showed that the N-CDs possessed good optical properties (QY = 32%) and excitation dependent multi-color emission. By exciting with 390 nm, the strong selective interaction of VB 12 with N-CDs could result in a sharp decrease in the luminescence of N-CDs at 567 nm. An efficient fluorescence sensor in aqueous solution was constructed which could linearly respond VB 12 in wide concentration ranges of 0–90 μM and 140–250 μM. The linear correlation coefficients of N-CDs and VB 12 were 0.9950 and 0.9968, respectively, and the detection limit was 0.119 μM. N-CDs were performed for sensitive determination of VB 12 in real samples. Moreover, the N-CDs were exploited to image cell. This N-CDs was a sensitive fluorescence probe to monitor VB 12 and presented prospective potential in living cells imaging. Graphical abstract Schematic diagram of the synthesis process and application research of N-CDs